Gunneras

Chilean Giant-rhubarb Chilean Giant-rhubarb Chilean Giant-rhubarb Chilean Giant-rhubarb

What are they?

The Gunneras are an interesting group of plants from the tropical and subtropical zones of the Southern Hemisphere. They are rather variable in appearance, though most have distinctly rounded 'peltate' leaves, with species ranging from creeping plants with leaves just a few centimetres across, to absolute giants, whose leaves may reach over three metres across! It is these giant species in particular that have become popular as garden plants and to which the name 'giant-rhubarb' has been applied, but the name falsely suggests a relationship to rhubarb, while also being of little value for the smaller species and I prefer Gunnera as a name - both shorter and more appropriate!

Where are they found?

As garden introductions, occasional cast-outs may turn up on waste ground or roadsides, but these are naturally plants of wet places and may turn up in a range of wetland habitats. In Ireland, Gunneras are now a major invasive species that are threatening native plant communities and the appearance of these plants (beautiful as they are) on the margins of the Norfolk Broads should give cause for concern.

Identification

The rather rhubarb-like appearance, coupled with spikey leaf stalks and unusual flower spikes is distinctive, but separation from other, as yet unrecorded species (such as Gunnera manicata) can be difficult.



Chilean Giant-rhubarb      Gunnera tinctoria

Introduced as a garden ornamental and occasionally found spreading into neighbouring wetland areas. Flowers May to August. Huge plants with leaves growing to 2.5 metres in height from a central rootstock. Leaves die down in winter, leaving peculiar, gnarly stumps covered in dense hairs. Individual flowers are tiny, but appear in huge, fingered spikes up to a metre in length.

Chilean Giant-rhubarb Chilean Giant-rhubarb Chilean Giant-rhubarb Chilean Giant-rhubarb
Habit
Flower spike
Flower close-up
Spring emergence